alias_nbt.c@ 39101

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1	/*-
2	* Written by Atsushi Murai <amurai@spec.co.jp>
3	* Copyright (c) 1998, System Planning and Engineering Co.
4	* All rights reserved.
5	*
6	* Redistribution and use in source and binary forms, with or without
7	* modification, are permitted provided that the following conditions
8	* are met:
9	* 1. Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.
11	* 2. Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.
14	*
15	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25	* SUCH DAMAGE.
26	* TODO:
27	* oClean up.
28	* oConsidering for word alignment for other platform.
29	*/
30
31	#ifndef VBOX
32	#include <sys/cdefs.h>
33	__FBSDID("$FreeBSD: src/sys/netinet/libalias/alias_nbt.c,v 1.20.8.1 2009/04/15 03:14:26 kensmith Exp $");
34
35	/*
36	alias_nbt.c performs special processing for NetBios over TCP/IP
37	sessions by UDP.
38
39	Initial version: May, 1998 (Atsushi Murai <amurai@spec.co.jp>)
40
41	See HISTORY file for record of revisions.
42	*/
43
44	/* Includes */
45	#ifdef _KERNEL
46	#include <sys/param.h>
47	#include <sys/systm.h>
48	#include <sys/kernel.h>
49	#include <sys/module.h>
50	#else
51	#include <errno.h>
52	#include <sys/types.h>
53	#include <stdio.h>
54	#endif
55
56	#include <netinet/in_systm.h>
57	#include <netinet/in.h>
58	#include <netinet/ip.h>
59	#include <netinet/udp.h>
60
61	#ifdef _KERNEL
62	#include <netinet/libalias/alias_local.h>
63	#include <netinet/libalias/alias_mod.h>
64	#else
65	#include "alias_local.h"
66	#include "alias_mod.h"
67	#endif
68	#else /VBOX/
69	# include <iprt/ctype.h>
70	# include <slirp.h>
71	# include "alias_local.h"
72	# include "alias_mod.h"
73	# define isprint RT_C_IS_PRINT
74	#endif /VBOX/
75
76	#define NETBIOS_NS_PORT_NUMBER 137
77	#define NETBIOS_DGM_PORT_NUMBER 138
78
79	static int
80	AliasHandleUdpNbt(struct libalias , struct ip , struct alias_link *,
81	struct in_addr *, u_short);
82
83	static int
84	AliasHandleUdpNbtNS(struct libalias , struct ip , struct alias_link *,
85	struct in_addr , u_short , struct in_addr , u_short );
86	static int
87	fingerprint1(struct libalias la, struct ip pip, struct alias_data *ah)
88	{
89
90	#ifdef VBOX
91	NOREF(la);
92	NOREF(pip);
93	#endif
94	if (ah->dport == NULL \|\| ah->sport == NULL \|\| ah->lnk == NULL \|\|
95	ah->aaddr == NULL \|\| ah->aport == NULL)
96	return (-1);
97	if (ntohs(*ah->dport) == NETBIOS_DGM_PORT_NUMBER
98	\|\| ntohs(*ah->sport) == NETBIOS_DGM_PORT_NUMBER)
99	return (0);
100	return (-1);
101	}
102
103	static int
104	protohandler1(struct libalias la, struct ip pip, struct alias_data *ah)
105	{
106
107	AliasHandleUdpNbt(la, pip, ah->lnk, ah->aaddr, *ah->aport);
108	return (0);
109	}
110
111	static int
112	fingerprint2(struct libalias la, struct ip pip, struct alias_data *ah)
113	{
114
115	#ifdef VBOX
116	NOREF(la);
117	NOREF(pip);
118	#endif
119	if (ah->dport == NULL \|\| ah->sport == NULL \|\| ah->lnk == NULL \|\|
120	ah->aaddr == NULL \|\| ah->aport == NULL)
121	return (-1);
122	if (ntohs(*ah->dport) == NETBIOS_NS_PORT_NUMBER
123	\|\| ntohs(*ah->sport) == NETBIOS_NS_PORT_NUMBER)
124	return (0);
125	return (-1);
126	}
127
128	static int
129	protohandler2in(struct libalias la, struct ip pip, struct alias_data *ah)
130	{
131
132	AliasHandleUdpNbtNS(la, pip, ah->lnk, ah->aaddr, ah->aport,
133	ah->oaddr, ah->dport);
134	return (0);
135	}
136
137	static int
138	protohandler2out(struct libalias la, struct ip pip, struct alias_data *ah)
139	{
140
141	AliasHandleUdpNbtNS(la, pip, ah->lnk, &pip->ip_src, ah->sport,
142	ah->aaddr, ah->aport);
143	return (0);
144	}
145
146	/* Kernel module definition. */
147	#ifndef VBOX
148	struct proto_handler handlers[] = {
149	{
150	.pri = 130,
151	.dir = IN\|OUT,
152	.proto = UDP,
153	.fingerprint = &fingerprint1,
154	.protohandler = &protohandler1
155	},
156	{
157	.pri = 140,
158	.dir = IN,
159	.proto = UDP,
160	.fingerprint = &fingerprint2,
161	.protohandler = &protohandler2in
162	},
163	{
164	.pri = 140,
165	.dir = OUT,
166	.proto = UDP,
167	.fingerprint = &fingerprint2,
168	.protohandler = &protohandler2out
169	},
170	{ EOH }
171	};
172	#else /* !VBOX */
173	#define handlers pData->nbt_module
174	#endif /VBOX/
175
176	#ifndef VBOX
177	static int
178	mod_handler(module_t mod, int type, void *data)
179	#else /!VBOX/
180	static int nbt_alias_handler(PNATState pData, int type);
181
182	int
183	nbt_alias_load(PNATState pData)
184	{
185	return nbt_alias_handler(pData, MOD_LOAD);
186	}
187
188	int
189	nbt_alias_unload(PNATState pData)
190	{
191	return nbt_alias_handler(pData, MOD_UNLOAD);
192	}
193	static int
194	nbt_alias_handler(PNATState pData, int type)
195	#endif /VBOX/
196	{
197	int error;
198	#ifdef VBOX
199	if (handlers == NULL)
200	handlers = RTMemAllocZ(4 * sizeof(struct proto_handler));
201	handlers[0].pri = 130;
202	handlers[0].dir = IN\|OUT;
203	handlers[0].proto = UDP;
204	handlers[0].fingerprint = &fingerprint1;
205	handlers[0].protohandler = &protohandler1;
206
207
208	handlers[1].pri = 140;
209	handlers[1].dir = IN;
210	handlers[1].proto = UDP;
211	handlers[1].fingerprint = &fingerprint2;
212	handlers[1].protohandler = &protohandler2in;
213
214
215	handlers[2].pri = 140;
216	handlers[2].dir = OUT;
217	handlers[2].proto = UDP;
218	handlers[2].fingerprint = &fingerprint2;
219	handlers[2].protohandler = &protohandler2out;
220
221	handlers[3].pri = EOH;
222	#endif /VBOX/
223
224	switch (type) {
225	case MOD_LOAD:
226	error = 0;
227	#ifdef VBOX
228	LibAliasAttachHandlers(pData, handlers);
229	#else
230	LibAliasAttachHandlers(handlers);
231	#endif
232	break;
233	case MOD_UNLOAD:
234	error = 0;
235	#ifdef VBOX
236	LibAliasDetachHandlers(pData, handlers);
237	RTMemFree(handlers);
238	handlers = NULL;
239	#else
240	LibAliasDetachHandlers(handlers);
241	#endif
242	break;
243	default:
244	error = EINVAL;
245	}
246	return (error);
247	}
248
249	#ifndef VBOX
250	#ifdef _KERNEL
251	static
252	#endif
253	moduledata_t alias_mod = {
254	"alias_nbt", mod_handler, NULL
255	};
256	#endif /!VBOX/
257
258	#ifdef _KERNEL
259	DECLARE_MODULE(alias_nbt, alias_mod, SI_SUB_DRIVERS, SI_ORDER_SECOND);
260	MODULE_VERSION(alias_nbt, 1);
261	MODULE_DEPEND(alias_nbt, libalias, 1, 1, 1);
262	#endif
263
264	typedef struct {
265	struct in_addr oldaddr;
266	u_short oldport;
267	struct in_addr newaddr;
268	u_short newport;
269	u_short *uh_sum;
270	} NBTArguments;
271
272	typedef struct {
273	unsigned char type;
274	unsigned char flags;
275	u_short id;
276	struct in_addr source_ip;
277	u_short source_port;
278	u_short len;
279	u_short offset;
280	} NbtDataHeader;
281
282	#define OpQuery 0
283	#define OpUnknown 4
284	#define OpRegist 5
285	#define OpRelease 6
286	#define OpWACK 7
287	#define OpRefresh 8
288	typedef struct {
289	#ifndef VBOX
290	u_short nametrid;
291	u_short dir: 1, opcode:4, nmflags:7, rcode:4;
292	#else
293	unsigned nametrid:16;
294	unsigned dir: 1, opcode:4, nmflags:7, rcode:4;
295	#endif
296	u_short qdcount;
297	u_short ancount;
298	u_short nscount;
299	u_short arcount;
300	} NbtNSHeader;
301	AssertCompileSize(NbtNSHeader, 12);
302
303	#define FMT_ERR 0x1
304	#define SRV_ERR 0x2
305	#define IMP_ERR 0x4
306	#define RFS_ERR 0x5
307	#define ACT_ERR 0x6
308	#define CFT_ERR 0x7
309
310
311	#ifdef LIBALIAS_DEBUG
312	static void
313	PrintRcode(u_char rcode)
314	{
315
316	switch (rcode) {
317	case FMT_ERR:
318	printf("\nFormat Error.");
319	case SRV_ERR:
320	printf("\nSever failure.");
321	case IMP_ERR:
322	printf("\nUnsupported request error.\n");
323	case RFS_ERR:
324	printf("\nRefused error.\n");
325	case ACT_ERR:
326	printf("\nActive error.\n");
327	case CFT_ERR:
328	printf("\nName in conflict error.\n");
329	default:
330	printf("\n?%c?=%0x\n", '?', rcode);
331
332	}
333	}
334
335	#endif
336
337
338	/* Handling Name field */
339	static u_char *
340	AliasHandleName(u_char * p, char *pmax)
341	{
342
343	u_char *s;
344	u_char c;
345	int compress;
346
347	/* Following length field */
348
349	if (p == NULL \|\| (char *)p >= pmax)
350	return (NULL);
351
352	if (*p & 0xc0) {
353	p = p + 2;
354	if ((char *)p > pmax)
355	return (NULL);
356	return ((u_char *) p);
357	}
358	while ((*p & 0x3f) != 0x00) {
359	s = p + 1;
360	if (*p == 0x20)
361	compress = 1;
362	else
363	compress = 0;
364
365	/* Get next length field */
366	p = (u_char ) (p + (p & 0x3f) + 1);
367	if ((char *)p > pmax) {
368	p = NULL;
369	break;
370	}
371	#ifdef LIBALIAS_DEBUG
372	printf(":");
373	#endif
374	while (s < p) {
375	if (compress == 1) {
376	c = (u_char) (((((s & 0x0f) << 4) \| ((s + 1) & 0x0f)) - 0x11));
377	#ifdef LIBALIAS_DEBUG
378	if (isprint(c))
379	printf("%c", c);
380	else
381	printf("<0x%02x>", c);
382	#endif
383	s += 2;
384	} else {
385	#ifdef LIBALIAS_DEBUG
386	printf("%c", *s);
387	#endif
388	s++;
389	}
390	}
391	#ifdef LIBALIAS_DEBUG
392	printf(":");
393	fflush(stdout);
394	#endif
395	}
396
397	/* Set up to out of Name field */
398	if (p == NULL \|\| (char *)p >= pmax)
399	p = NULL;
400	else
401	p++;
402	return ((u_char *) p);
403	}
404
405	/*
406	* NetBios Datagram Handler (IP/UDP)
407	*/
408	#define DGM_DIRECT_UNIQ 0x10
409	#define DGM_DIRECT_GROUP 0x11
410	#define DGM_BROADCAST 0x12
411	#define DGM_ERROR 0x13
412	#define DGM_QUERY 0x14
413	#define DGM_POSITIVE_RES 0x15
414	#define DGM_NEGATIVE_RES 0x16
415
416	static int
417	AliasHandleUdpNbt(
418	struct libalias *la,
419	struct ip pip, / IP packet to examine/patch */
420	struct alias_link *lnk,
421	struct in_addr *alias_address,
422	u_short alias_port
423	)
424	{
425	struct udphdr *uh;
426	NbtDataHeader *ndh;
427	u_char *p = NULL;
428	char *pmax;
429
430	(void)la;
431	(void)lnk;
432
433	/* Calculate data length of UDP packet */
434	uh = (struct udphdr *)ip_next(pip);
435	pmax = (char *)uh + ntohs(uh->uh_ulen);
436
437	ndh = (NbtDataHeader *)udp_next(uh);
438	if ((char *)(ndh + 1) > pmax)
439	return (-1);
440	#ifdef LIBALIAS_DEBUG
441	printf("\nType=%02x,", ndh->type);
442	#endif
443	switch (ndh->type) {
444	case DGM_DIRECT_UNIQ:
445	case DGM_DIRECT_GROUP:
446	case DGM_BROADCAST:
447	p = (u_char *) ndh + 14;
448	p = AliasHandleName(p, pmax); /* Source Name */
449	p = AliasHandleName(p, pmax); /* Destination Name */
450	break;
451	case DGM_ERROR:
452	p = (u_char *) ndh + 11;
453	break;
454	case DGM_QUERY:
455	case DGM_POSITIVE_RES:
456	case DGM_NEGATIVE_RES:
457	p = (u_char *) ndh + 10;
458	p = AliasHandleName(p, pmax); /* Destination Name */
459	break;
460	}
461	if (p == NULL \|\| (char *)p > pmax)
462	p = NULL;
463	#ifdef LIBALIAS_DEBUG
464	printf("%s:%d-->", inet_ntoa(ndh->source_ip), ntohs(ndh->source_port));
465	#endif
466	/* Doing an IP address and Port number Translation */
467	if (uh->uh_sum != 0) {
468	int acc;
469	u_short *sptr;
470
471	acc = ndh->source_port;
472	acc -= alias_port;
473	sptr = (u_short *) & (ndh->source_ip);
474	acc += *sptr++;
475	acc += *sptr;
476	sptr = (u_short *) alias_address;
477	acc -= *sptr++;
478	acc -= *sptr;
479	ADJUST_CHECKSUM(acc, uh->uh_sum);
480	}
481	ndh->source_ip = *alias_address;
482	ndh->source_port = alias_port;
483	#ifdef LIBALIAS_DEBUG
484	printf("%s:%d\n", inet_ntoa(ndh->source_ip), ntohs(ndh->source_port));
485	fflush(stdout);
486	#endif
487	return ((p == NULL) ? -1 : 0);
488	}
489
490	/* Question Section */
491	#define QS_TYPE_NB 0x0020
492	#define QS_TYPE_NBSTAT 0x0021
493	#define QS_CLAS_IN 0x0001
494	typedef struct {
495	u_short type; /* The type of Request */
496	u_short class; /* The class of Request */
497	} NBTNsQuestion;
498
499	static u_char *
500	AliasHandleQuestion(
501	u_short count,
502	NBTNsQuestion * q,
503	char *pmax,
504	NBTArguments * nbtarg)
505	{
506
507	(void)nbtarg;
508
509	while (count != 0) {
510	/* Name Filed */
511	q = (NBTNsQuestion ) AliasHandleName((u_char ) q, pmax);
512
513	if (q == NULL \|\| (char *)(q + 1) > pmax) {
514	q = NULL;
515	break;
516	}
517	/* Type and Class filed */
518	switch (ntohs(q->type)) {
519	case QS_TYPE_NB:
520	case QS_TYPE_NBSTAT:
521	q = q + 1;
522	break;
523	default:
524	#ifdef LIBALIAS_DEBUG
525	printf("\nUnknown Type on Question %0x\n", ntohs(q->type));
526	#endif
527	break;
528	}
529	count--;
530	}
531
532	/* Set up to out of Question Section */
533	return ((u_char *) q);
534	}
535
536	/* Resource Record */
537	#define RR_TYPE_A 0x0001
538	#define RR_TYPE_NS 0x0002
539	#define RR_TYPE_NULL 0x000a
540	#define RR_TYPE_NB 0x0020
541	#define RR_TYPE_NBSTAT 0x0021
542	#define RR_CLAS_IN 0x0001
543	#define SizeOfNsResource 8
544	typedef struct {
545	u_short type;
546	u_short class;
547	unsigned int ttl;
548	u_short rdlen;
549	} NBTNsResource;
550
551	#define SizeOfNsRNB 6
552	typedef struct {
553	#ifndef VBOX
554	u_short g: 1 , ont:2, resv:13;
555	#else
556	unsigned g: 1 , ont:2, resv:13;
557	#endif
558	struct in_addr addr;
559	} NBTNsRNB;
560	AssertCompileSize(NBTNsRNB, 8);
561
562	static u_char *
563	AliasHandleResourceNB(
564	NBTNsResource * q,
565	char *pmax,
566	NBTArguments * nbtarg)
567	{
568	NBTNsRNB *nb;
569	u_short bcount;
570
571	if (q == NULL \|\| (char *)(q + 1) > pmax)
572	return (NULL);
573	/* Check out a length */
574	bcount = ntohs(q->rdlen);
575
576	/* Forward to Resource NB position */
577	nb = (NBTNsRNB ) ((u_char ) q + SizeOfNsResource);
578
579	/* Processing all in_addr array */
580	#ifdef LIBALIAS_DEBUG
581	printf("NB rec[%s", inet_ntoa(nbtarg->oldaddr));
582	printf("->%s, %dbytes] ", inet_ntoa(nbtarg->newaddr), bcount);
583	#endif
584	while (nb != NULL && bcount != 0) {
585	if ((char *)(nb + 1) > pmax) {
586	nb = NULL;
587	break;
588	}
589	#ifdef LIBALIAS_DEBUG
590	printf("<%s>", inet_ntoa(nb->addr));
591	#endif
592	if (!bcmp(&nbtarg->oldaddr, &nb->addr, sizeof(struct in_addr))) {
593	if (*nbtarg->uh_sum != 0) {
594	int acc;
595	u_short *sptr;
596
597	sptr = (u_short *) & (nb->addr);
598	acc = *sptr++;
599	acc += *sptr;
600	sptr = (u_short *) & (nbtarg->newaddr);
601	acc -= *sptr++;
602	acc -= *sptr;
603	ADJUST_CHECKSUM(acc, *nbtarg->uh_sum);
604	}
605	nb->addr = nbtarg->newaddr;
606	#ifdef LIBALIAS_DEBUG
607	printf("O");
608	#endif
609	}
610	#ifdef LIBALIAS_DEBUG
611	else {
612	printf(".");
613	}
614	#endif
615	nb = (NBTNsRNB ) ((u_char ) nb + SizeOfNsRNB);
616	bcount -= SizeOfNsRNB;
617	}
618	if (nb == NULL \|\| (char *)(nb + 1) > pmax) {
619	nb = NULL;
620	}
621	return ((u_char *) nb);
622	}
623
624	#define SizeOfResourceA 6
625	typedef struct {
626	struct in_addr addr;
627	} NBTNsResourceA;
628
629	static u_char *
630	AliasHandleResourceA(
631	NBTNsResource * q,
632	char *pmax,
633	NBTArguments * nbtarg)
634	{
635	NBTNsResourceA *a;
636	u_short bcount;
637
638	if (q == NULL \|\| (char *)(q + 1) > pmax)
639	return (NULL);
640
641	/* Forward to Resource A position */
642	a = (NBTNsResourceA ) ((u_char ) q + sizeof(NBTNsResource));
643
644	/* Check out of length */
645	bcount = ntohs(q->rdlen);
646
647	/* Processing all in_addr array */
648	#ifdef LIBALIAS_DEBUG
649	printf("Arec [%s", inet_ntoa(nbtarg->oldaddr));
650	printf("->%s]", inet_ntoa(nbtarg->newaddr));
651	#endif
652	while (bcount != 0) {
653	if (a == NULL \|\| (char *)(a + 1) > pmax)
654	return (NULL);
655	#ifdef LIBALIAS_DEBUG
656	printf("..%s", inet_ntoa(a->addr));
657	#endif
658	if (!bcmp(&nbtarg->oldaddr, &a->addr, sizeof(struct in_addr))) {
659	if (*nbtarg->uh_sum != 0) {
660	int acc;
661	u_short *sptr;
662
663	sptr = (u_short ) & (a->addr); / Old */
664	acc = *sptr++;
665	acc += *sptr;
666	sptr = (u_short ) & nbtarg->newaddr; / New */
667	acc -= *sptr++;
668	acc -= *sptr;
669	ADJUST_CHECKSUM(acc, *nbtarg->uh_sum);
670	}
671	a->addr = nbtarg->newaddr;
672	}
673	a++; /* XXXX */
674	bcount -= SizeOfResourceA;
675	}
676	if (a == NULL \|\| (char *)(a + 1) > pmax)
677	a = NULL;
678	return ((u_char *) a);
679	}
680
681	typedef struct {
682	#ifndef VBOX
683	u_short opcode:4, flags:8, resv:4;
684	#else
685	u_short hidden; /* obviously not needed */
686	#endif
687	} NBTNsResourceNULL;
688	AssertCompileSize(NBTNsResourceNULL, 2);
689
690	static u_char *
691	AliasHandleResourceNULL(
692	NBTNsResource * q,
693	char *pmax,
694	NBTArguments * nbtarg)
695	{
696	NBTNsResourceNULL *n;
697	u_short bcount;
698
699	(void)nbtarg;
700
701	if (q == NULL \|\| (char *)(q + 1) > pmax)
702	return (NULL);
703
704	/* Forward to Resource NULL position */
705	n = (NBTNsResourceNULL ) ((u_char ) q + sizeof(NBTNsResource));
706
707	/* Check out of length */
708	bcount = ntohs(q->rdlen);
709
710	/* Processing all in_addr array */
711	while (bcount != 0) {
712	if ((char *)(n + 1) > pmax) {
713	n = NULL;
714	break;
715	}
716	n++;
717	bcount -= sizeof(NBTNsResourceNULL);
718	}
719	if ((char *)(n + 1) > pmax)
720	n = NULL;
721
722	return ((u_char *) n);
723	}
724
725	static u_char *
726	AliasHandleResourceNS(
727	NBTNsResource * q,
728	char *pmax,
729	NBTArguments * nbtarg)
730	{
731	NBTNsResourceNULL *n;
732	u_short bcount;
733
734	(void)nbtarg;
735
736	if (q == NULL \|\| (char *)(q + 1) > pmax)
737	return (NULL);
738
739	/* Forward to Resource NULL position */
740	n = (NBTNsResourceNULL ) ((u_char ) q + sizeof(NBTNsResource));
741
742	/* Check out of length */
743	bcount = ntohs(q->rdlen);
744
745	/* Resource Record Name Filed */
746	q = (NBTNsResource ) AliasHandleName((u_char ) n, pmax); /* XXX */
747
748	if (q == NULL \|\| (char )((u_char ) n + bcount) > pmax)
749	return (NULL);
750	else
751	return ((u_char *) n + bcount);
752	}
753
754	typedef struct {
755	u_short numnames;
756	} NBTNsResourceNBSTAT;
757
758	static u_char *
759	AliasHandleResourceNBSTAT(
760	NBTNsResource * q,
761	char *pmax,
762	NBTArguments * nbtarg)
763	{
764	NBTNsResourceNBSTAT *n;
765	u_short bcount;
766
767	(void)nbtarg;
768
769	if (q == NULL \|\| (char *)(q + 1) > pmax)
770	return (NULL);
771
772	/* Forward to Resource NBSTAT position */
773	n = (NBTNsResourceNBSTAT ) ((u_char ) q + sizeof(NBTNsResource));
774
775	/* Check out of length */
776	bcount = ntohs(q->rdlen);
777
778	if (q == NULL \|\| (char )((u_char ) n + bcount) > pmax)
779	return (NULL);
780	else
781	return ((u_char *) n + bcount);
782	}
783
784	static u_char *
785	AliasHandleResource(
786	u_short count,
787	NBTNsResource * q,
788	char *pmax,
789	NBTArguments
790	* nbtarg)
791	{
792	while (count != 0) {
793	/* Resource Record Name Filed */
794	q = (NBTNsResource ) AliasHandleName((u_char ) q, pmax);
795
796	if (q == NULL \|\| (char *)(q + 1) > pmax)
797	break;
798	#ifdef LIBALIAS_DEBUG
799	printf("type=%02x, count=%d\n", ntohs(q->type), count);
800	#endif
801
802	/* Type and Class filed */
803	switch (ntohs(q->type)) {
804	case RR_TYPE_NB:
805	q = (NBTNsResource *) AliasHandleResourceNB(
806	q,
807	pmax,
808	nbtarg
809	);
810	break;
811	case RR_TYPE_A:
812	q = (NBTNsResource *) AliasHandleResourceA(
813	q,
814	pmax,
815	nbtarg
816	);
817	break;
818	case RR_TYPE_NS:
819	q = (NBTNsResource *) AliasHandleResourceNS(
820	q,
821	pmax,
822	nbtarg
823	);
824	break;
825	case RR_TYPE_NULL:
826	q = (NBTNsResource *) AliasHandleResourceNULL(
827	q,
828	pmax,
829	nbtarg
830	);
831	break;
832	case RR_TYPE_NBSTAT:
833	q = (NBTNsResource *) AliasHandleResourceNBSTAT(
834	q,
835	pmax,
836	nbtarg
837	);
838	break;
839	default:
840	#ifdef LIBALIAS_DEBUG
841	printf(
842	"\nUnknown Type of Resource %0x\n",
843	ntohs(q->type)
844	);
845	fflush(stdout);
846	#endif
847	break;
848	}
849	count--;
850	}
851	return ((u_char *) q);
852	}
853
854	static int
855	AliasHandleUdpNbtNS(
856	struct libalias *la,
857	struct ip pip, / IP packet to examine/patch */
858	struct alias_link *lnk,
859	struct in_addr *alias_address,
860	u_short * alias_port,
861	struct in_addr *original_address,
862	u_short * original_port)
863	{
864	struct udphdr *uh;
865	NbtNSHeader *nsh;
866	u_char *p;
867	char *pmax;
868	NBTArguments nbtarg;
869
870	(void)la;
871	(void)lnk;
872
873	/* Set up Common Parameter */
874	nbtarg.oldaddr = *alias_address;
875	nbtarg.oldport = *alias_port;
876	nbtarg.newaddr = *original_address;
877	nbtarg.newport = *original_port;
878
879	/* Calculate data length of UDP packet */
880	uh = (struct udphdr *)ip_next(pip);
881	nbtarg.uh_sum = &(uh->uh_sum);
882	nsh = (NbtNSHeader *)udp_next(uh);
883	p = (u_char *) (nsh + 1);
884	pmax = (char *)uh + ntohs(uh->uh_ulen);
885
886	if ((char *)(nsh + 1) > pmax)
887	return (-1);
888
889	#ifdef LIBALIAS_DEBUG
890	printf(" [%s] ID=%02x, op=%01x, flag=%02x, rcode=%01x, qd=%04x"
891	", an=%04x, ns=%04x, ar=%04x, [%d]-->",
892	nsh->dir ? "Response" : "Request",
893	nsh->nametrid,
894	nsh->opcode,
895	nsh->nmflags,
896	nsh->rcode,
897	ntohs(nsh->qdcount),
898	ntohs(nsh->ancount),
899	ntohs(nsh->nscount),
900	ntohs(nsh->arcount),
901	(u_char ) p - (u_char ) nsh
902	);
903	#endif
904
905	/* Question Entries */
906	if (ntohs(nsh->qdcount) != 0) {
907	p = AliasHandleQuestion(
908	ntohs(nsh->qdcount),
909	(NBTNsQuestion *) p,
910	pmax,
911	&nbtarg
912	);
913	}
914	/* Answer Resource Records */
915	if (ntohs(nsh->ancount) != 0) {
916	p = AliasHandleResource(
917	ntohs(nsh->ancount),
918	(NBTNsResource *) p,
919	pmax,
920	&nbtarg
921	);
922	}
923	/* Authority Resource Recodrs */
924	if (ntohs(nsh->nscount) != 0) {
925	p = AliasHandleResource(
926	ntohs(nsh->nscount),
927	(NBTNsResource *) p,
928	pmax,
929	&nbtarg
930	);
931	}
932	/* Additional Resource Recodrs */
933	if (ntohs(nsh->arcount) != 0) {
934	p = AliasHandleResource(
935	ntohs(nsh->arcount),
936	(NBTNsResource *) p,
937	pmax,
938	&nbtarg
939	);
940	}
941	#ifdef LIBALIAS_DEBUG
942	PrintRcode(nsh->rcode);
943	#endif
944	return ((p == NULL) ? -1 : 0);
945	}

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source: vbox/trunk/src/VBox/Devices/Network/slirp/libalias/alias_nbt.c@ 39101

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